Hethod of kntting on straight-bar knitting machines



y 1942- H. W. START ETAL 2,233,771

METHOD OF KNITTING ON STRA'IGHT-BAR KNITTING MACHINES Filed June 19, 1941 Fig 4 seamen or an Wilfred start. Carlton, and

Wilford, England, assignors to George horn and Sons Limited, Nottingham, Eng

Application l9, ran, Serial No. 393,2'515 lln Great Eritain April i'o s invention elates to improvements in or sht==bar {knitting machines to irnit the heel tabs in a rising a leg, instep and sole and which comprise two groups of nee. dies and associated knitting elements, spaced the requisite distance apart and wherein the slur coclrs and thread carriers associated with each group move in opposite directions and to a method oi operating such machines to provide better selvedge edges to the heel tabs.

in machines or the type described, the heel tabs are shaped by means oi the narrowing points providedior the purpose and these points are brought into action'at the appropriate times to move a series of loops at the outer sides of the tabs inwardly two needles and normally this operation takes place when the thread carriers are disposed at the outer edges of the tabs.

When the loops are being transferred during the narrowing operation, the points are first brought down into engagement with the needles when the loops thereon are below the points of the beards. The points and needles are lowered together until the tops of the needles are below the knocking-over bits so that the loops are transferred onto the points. The sinkers are withdrawn and the points and needles raised until the points are clear of the knocking-over bits.

During this movement, the work on the remainq ing needles will rise up with the needles. The points are then moved laterally inwards the required distance and then re-engaged with the needles to replace the loops thereon. At this stage, the work on the needles is above the ends of the sinkers and in order to replace the loops on the needles the points and the needles are lowered'and the sinkers advanced until .they are over the work. The needles are then raised and they will pass up through the loops on the points, the work being held down by the underside of the sinkers.

The needles are raised until the loops are below the points of the beards when the points are raised out of action and the loops left on the needle stems. Knitting is then continued in the usual manner until the next narrowing takes place.

It will be seen that when the narrowing takes place the yarn will extend from the outermost loop to the thread carrier and that when the loops on the points are moved inwardly the tension on the thread will exert a slight pull on the work and this pull will also be increased by any friction between the thread and the thread guide.

(or. se -e2) When the points and needles move down to gether, after the points have been moved in. the required distance. the pull exerted by the yarn will tend to pull the loops on the points up the latter.

.Owing to the speed which this type of ma chine is run this tendency to pull the loops on the points up the latter is greatly increased and is particularly noticeable when working silk or artificial sills. As a result oi this tendency, the loops do not always go down with the points and as the sinkers are advanced at this particular time the ends oi the latter strike the work held by the points and penetrate it causing damage to the heel tab, usually close to the selvedge edge which is held by the yarn attachedwhereto.

Should however the sinkers pass over the work without damage thereto then the yarn from the outer loop on the needles, which has now been moved in two needles, extends across to the thread carrier which remains in the position at which it was stopped before the narrowing oper ation was started. There is, therefore, the risk passes round the end of the sinker and a large loop'is formed on the 'selvedge edge when the course is subsequently knitted. The heel tabs may thus be formed with slack loops at intervals and an uneven selvedge edge produced which will prevent the formation of neat seams when the parts are subsequently seamed together. This tendency to form long loops at the selvedge is due to the speed at which this type of machine is run, and a similar result may be obtained at the inner selvedse edge.

The object of the present invention is to prevent any possibility of the work being damaged by the sinkers and produce a neat and even selvedg'e on both sides of the heel tabs without having to reduce the speed at which the machine can be run.

According to this invention, when narrowing takes place the thread carriers are stopped at the inner sides of the heel tabs and a specially shaped sinker is provided at the inner side of each group to ensure that the yarn passes between the correct sinkers at this point, and as a result damage to the work the slnkers is obviated and normal sized loops are produced on each selvedge cf th heel tabs.

Referring to theaccompanying drawing:

Figs.- 1 to 4 show diagrammatically the method of narrowing as adopted hitherto,

Fig. 5 shows diagrammatically the position of the loops when narrowing according to the present invention and Fig. 6 is a side view showing the shape of the sinker disposed at the inner side of each group of sinkers.

Like letters indicate like parts throughout the drawing.

In narrowing as hitherto carried out, the narrowing points A are moved into engagement with the needles B when the latter are in their raised position and the work is on the knocking-over bits C. The points and needles are then lowered into the position shown in Fig. 1 when a series of loops at the outer edge of the work are transferred as shown onto the points A, the thread guide D being stationery and disposed at the outer side of the work, that is, at the side where the narrowing takes place. When the loops have been. transferred to the points, the latter and the needles are raised together until the points are clear of the knocking-over bits when the needles are moved back slightly, the points moved inwards two needles and then re-engaged by the needles as shown in Fig. 2. The points and needles are then lowered together until the work is on the knocking-over hits, the sinkers E are then advanced over the work to hold the latter down while the needles are raised. Those needles in engagement with the points pass up through the loops thereon after which the points are withdrawn leaving the loops on the needles.

Owing to the tension on the yarn, the friction of the thread in the guide and the speed at which this class of machine is run there is a tendency to draw the loops up the points, as shown in Fig. 3, when the points and needles are lowered together as previously explained so that when the sinkers are advanced they move into the work held by the points and cut it. If the loops on the points retain their correct position the yarn from the outer loop passes diagonally across the sinkers, as shown in Fig. 4, and the sinker E advances over the yarn so that when the next course is drawn the yarn passes round the sinker nose as indicated in dotted lines and a slack loop is formed at the selvedge edge. 4

In carrying out this invention, the narrowings necessary to shape the heel tabs are always made in courses which are drawn when the thread carriers move from the outside to the inside of each group of needles so that during the narrowing operation the thread carriers stand at the inside of each group, as shown in Fig. 5. The narrowing takes place in the usual manner at the outer side of the heel tabs and as a result, the outermost loop is not connected by the yarn to the thread carrier as in the method of operation hitherto adopted.

There is, therefore, no tendency for the loops taken by the points to ride up the latterwhen they are being lowered to replace the loops on the needles as previously explained, and as a result the loops will go down with the points and the possibility of the sinkers fouling the work and causing damage thereto is obviated. Furthermore. as the yarn does not extend from the outermost of the transferred loops as the thread carrier is disposed at the other end of the group of needles, there is no possibility of a sleek loop being formed at the outer edge of the heel tab which is formed with a perfect selvedge edge as the sinkers are only withdrawn clear of the work during the narrowing operation.

The selvedge on the inner side of the heel tabs is straight and is produced by the innermost needle 13 (see Fig. 5), of the groups. In order to produce a neat inner selvedge the innermost sinker iii is made with a shorter nose E than the remainder of the sinkers as shown in Fig. 6.

When, therefore, the sinkers are advanced over the work as the needles rise at the completion of the narrowing operation the work is held down by the undersides of the sinker noses, as shown in Fig. 6, and the yarn extends from the innermost needle up to the thread guide, as shown. The short nose E on the innermost sinker E does not engage with the yarn until the work is held by the undersides of the other sinkers and will, therefore, always pass under the yam'so that the innermost needle draws a loopof normal length.

Similarly, when the needles move down to knit in the usual manner, the loops are drawn down ofi the sinker noses and down through the work which is held by the knocking-over bits. The yarn now extends from the last loop formed on the inner needle up to the thread carrier, as shown in Fig. 5. As the needles rise, the loops are engaged by the undersides of the sinkers and the innermost sinker will pass under the yarn so that loops of normal length will always be formed by the innermost needle and a neat selvege edge produced. The shortening of the innermost sinker nose also permits of the thread guide being moved further inwards without danger of forming a slack loop.

The production of neat selvedges facilitates the running of the work on the points of the seaming machine and assists in the production of a neat seam when the parts are ultimately seamed together.

What we claim as our invention is:

1. In knitting heel tabs to a stocking blank on a straight-bar knitting machine, the method of producing neat selvedge edges to the heel tabs by making the narrowings therein when the thread guides are disposed at the inner sides of the heel tabs and adapting the innermost sinker of each group to ensure the formation of 9. normal loop on the innermost needle 01' each group.

2. In knitting heel tabs to a stocking blank on a straight-bar knitting machine, the method of producing neat selvedge edges to the heel tabs by making the narrowingstherein to shape the outer sides of the heel tabsgwhen the thread guides are disposed at the inner sides of the heel tabs and ensuring the formation of normal sized loops by the innermost needle of each group by providing the innermost sinker of each group with a short- 

